1. Field of the Invention
The present invention pertains to the processing of product filled containers and more particularly relates to a method and apparatus for purging air from product filled containers prior to the sealing thereof.
2. Description of the Prior Art
It is well known in the art to purge air and cooking gases from flexible containers having their upper ends closed, but not sealed, by moving the containers alternately through steam and water baths during processing thereby progressively forcing the noncondensible gases out of the containers before sealing the containers. Wilson U.S. Pat. No. 3,501,318, which issued on Mar. 17, 1970, and is incorporated by reference herein, discloses such a process.
The patent to White U.S. Pat. No. 1,920,539, which issued on Aug. 1, 1933, discloses a method wherein filled rigid containers, and separate caps, are passed through a steam zone at 212.degree. F for the purpose of replacing the air in the headspace of the containers and the caps with steam. While the cap is being sealed on the container, the container is said to be moved to a cooler zone so that the steam in the headspace condenses thereby reducing the internal pressure below atmospheric pressure.